System and method for protecting assets using wide area network connection

BACKGROUND OF THE INVENTION

p-00021. Technical Field

p-0003The present invention relates to a system, method, and program product that protects information and computer assets using a wide area network connection of an information handling system.

p-00042. Description of the Related Art

p-0005Asset protection is of increased importance with most every type of organization. Not only are the hardware assets, such as laptop computers and accessories, valuable and important to protect, but often the information assets stored on the computer system is even more valuable. Information assets may include proprietary intellectual property of an organization that is extremely valuable. If this valuable information falls into the wrong hands, such as those of a competitor, the organization is likely to suffer irreparable harm.

p-0006Always-on protection employing network technology is useful in protecting assets and information assets. Commands can be sent to an information handling system, such as a laptop computer, instructing the computer to lock the system. Moreover, systems with GPS capabilities can use the network to inform a user of the asset's location. In this manner, the asset can be instructed to enter a locked mode to protect the information assets if the system is lost, stolen, or its whereabouts are otherwise unaccounted for. Using GPS technology, the system can also instruct the owner of its whereabouts so that it can be retrieved by the owner or law enforcement. A challenge, however, to always-on asset protection is that the protection can be thwarted if the network adapter used to communicate with the system is removed or otherwise disabled.

SUMMARY

p-0007It has been discovered that the aforementioned challenges are resolved by detecting whether a network adapter has been removed from a computer system. If the network adapter, such as a wireless network adapter, has been removed from the computer system, then a tamper evident indicator (e.g., bit) is set in a nonvolatile memory area of the computer system. In addition, a hard drive password is set to a different password according to a hard drive password policy. The hard drive password controls access to files stored on the hard drive. In one embodiment, the hard drive password is set to a supervisory password. In this manner, a malevolent user, such as a thief of the computer system, attempting to thwart the asset protection mechanisms by removing the network adapter would be unable to access the files stored on the hard drive without the new hard drive password (such as the supervisory password). In one embodiment, the power-on password is also changed to a new password (e.g., a supervisory password). In this embodiment, the user would have to enter the new power-on password when initializing the computer system in order to access the files stored on the computer system.

p-0008The foregoing is a summary and thus contains, by necessity, simplifications, generalizations, and omissions of detail; consequently, those skilled in the art will appreciate that the summary is illustrative only and is not intended to be in any way limiting. Other aspects, inventive features, and advantages of the present invention, as defined solely by the claims, will become apparent in the non-limiting detailed description set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

p-0009The present invention may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings, wherein:

p-0010<figref idrefs="DRAWINGS">FIG. 1</figref> is a block diagram of a data processing system in which the methods described herein can be implemented;

p-0011<figref idrefs="DRAWINGS">FIG. 2</figref> provides an extension of the information handling system environment shown in <figref idrefs="DRAWINGS">FIG. 1</figref> to illustrate that the methods described herein can be performed on a wide variety of information handling systems which operate in a networked environment;

p-0012<figref idrefs="DRAWINGS">FIG. 3</figref> is a system diagram showing an information handling system with a network adapter receiving remote security commands over a computer network;

p-0013<figref idrefs="DRAWINGS">FIG. 4</figref> is a flowchart showing steps taken to setup policies used by the information handling system when the network adapter is removed;

p-0014<figref idrefs="DRAWINGS">FIG. 5</figref> is a flowchart showing steps taken when the network adapter is removed while the information handling system is operating; and

p-0015<figref idrefs="DRAWINGS">FIG. 6</figref> is a flowchart showing steps taken by the information handling system during initialization to check for tampering and the presence of the network adapter.

DETAILED DESCRIPTION

p-0016Certain specific details are set forth in the following description and figures to provide a thorough understanding of various embodiments of the invention. Certain well-known details often associated with computing and software technology are not set forth in the following disclosure, however, to avoid unnecessarily obscuring the various embodiments of the invention. Further, those of ordinary skill in the relevant art will understand that they can practice other embodiments of the invention without one or more of the details described below. Finally, while various methods are described with reference to steps and sequences in the following disclosure, the description as such is for providing a clear implementation of embodiments of the invention, and the steps and sequences of steps should not be taken as required to practice this invention. Instead, the following is intended to provide a detailed description of an example of the invention and should not be taken to be limiting of the invention itself. Rather, any number of variations may fall within the scope of the invention, which is defined by the claims that follow the description.

p-0017The following detailed description will generally follow the summary of the invention, as set forth above, further explaining and expanding the definitions of the various aspects and embodiments of the invention as necessary. To this end, this detailed description first sets forth a computing environment in <figref idrefs="DRAWINGS">FIG. 1</figref> that is suitable to implement the software and/or hardware techniques associated with the invention. A networked environment is illustrated in <figref idrefs="DRAWINGS">FIG. 2</figref> as an extension of the basic computing environment, to emphasize that modern computing techniques can be performed across multiple discrete devices.

p-0018<figref idrefs="DRAWINGS">FIG. 1</figref> illustrates information handling system <b>100</b> which is a simplified example of a computer system capable of performing the computing operations described herein. Information handling system <b>100</b> includes one or more processors <b>110</b> which are coupled to processor interface bus <b>112</b>. Processor interface bus <b>112</b> connects processors <b>110</b> to Northbridge <b>115</b>, which is also known as the Memory Controller Hub (MCH). Northbridge <b>115</b> is connected to system memory <b>120</b> and provides a means for processor(s) <b>110</b> to access the system memory. Graphics controller <b>125</b> is also connected to Northbridge <b>115</b>. In one embodiment, PCI Express bus <b>118</b> is used to connect Northbridge <b>115</b> to graphics controller <b>125</b>. Graphics controller <b>125</b> is connected to display device <b>130</b>, such as a computer monitor.

p-0019Northbridge <b>115</b> and Southbridge <b>135</b> are connected to each other using bus <b>119</b>. In one embodiment, the bus is a Direct Media Interface (DMI) bus that transfers data at high speeds in each direction between Northbridge <b>115</b> and Southbridge <b>135</b>. In another embodiment, a Peripheral Component Interconnect (PCI) bus is used to connect the Northbridge and the Southbridge. Southbridge <b>135</b>, also known as the I/O Controller Hub (ICH) is a chip that generally implements capabilities that operate at slower speeds than the capabilities provided by the Northbridge. Southbridge <b>135</b> typically provides various busses used to connect various components. These busses can include PCI and PCI Express busses, an ISA bus, a System Management Bus (SMBus or SMB), a Low Pin Count (LPC) bus. The LPC bus is often used to connect low-bandwidth devices, such as boot ROM <b>196</b> and “legacy” I/O devices (using a “super I/O” chip). The “legacy” I/O devices (<b>198</b>) can include serial and parallel ports, keyboard, mouse, floppy disk controller. The LPC bus is also used to connect Southbridge <b>135</b> to Trusted Platform Module (TPM) <b>195</b>. Other components often included in Southbridge <b>135</b> include a Direct Memory Access (DMA) controller, a Programmable Interrupt Controller (PIC), a storage device controller, which connects Southbridge <b>135</b> to nonvolatile storage device <b>300</b> such as a hybrid hard disk drive, using bus <b>184</b>.

p-0020ExpressCard <b>155</b> is a slot used to connect hot-pluggable devices to the information handling system. ExpressCard <b>155</b> supports both PCI Express and USB connectivity as it is connected to Southbridge <b>135</b> using both the Universal Serial Bus (USB) the PCI Express bus. Southbridge <b>135</b> includes USB Controller <b>140</b> that provides USB connectivity to devices that connect to the USB. These devices include webcam (camera) <b>150</b>, infrared (IR) receiver <b>148</b>, Bluetooth device <b>146</b> which provides for wireless personal area networks (PANs), keyboard and trackpad <b>144</b>, and other miscellaneous USB connected devices <b>142</b>, such as a mouse, removable nonvolatile storage device <b>145</b>, modems, network cards, ISDN connectors, fax, printers, USB hubs, and many other types of USB connected devices. While removable nonvolatile storage device <b>145</b> is shown as a USB-connected device, removable nonvolatile storage device <b>145</b> could be connected using a different interface, such as a Firewire interface, etc. Removable storage device <b>145</b> can also be a hybrid disk drive, such as hybrid disk drive <b>300</b> shown in <figref idrefs="DRAWINGS">FIGS. 3-6</figref>.

p-0021Wireless Local Area Network (LAN) device <b>175</b> is connected to Southbridge <b>135</b> via the PCI or PCI Express bus <b>172</b>. LAN device <b>175</b> typically implements one of the IEEE 802.11 standards of over-the-air modulation techniques that all use the same protocol to wireless communicate between information handling system <b>100</b> and another computer system or device. Optical storage device <b>190</b> is connected to Southbridge <b>135</b> using Serial ATA (SATA) bus <b>188</b>. Serial ATA adapters and devices communicate over a high-speed serial link. The Serial ATA bus is also used to connect Southbridge <b>135</b> to other forms of storage devices, such as hard disk drives. Audio circuitry <b>160</b>, such as a sound card, is connected to Southbridge <b>135</b> via bus <b>158</b>. Audio circuitry <b>160</b> is used to provide functionality such as audio line-in and optical digital audio in port <b>162</b>, optical digital output and headphone jack <b>164</b>, internal speakers <b>166</b>, and internal microphone <b>168</b>. Ethernet controller <b>170</b> is connected to Southbridge <b>135</b> using a bus, such as the PCI or PCI Express bus. Ethernet controller <b>170</b> is used to connect information handling system <b>100</b> with a computer network, such as a Local Area Network (LAN), the Internet, and other public and private computer networks.

p-0022While <figref idrefs="DRAWINGS">FIG. 1</figref> shows one information handling system, an information handling system may take many forms. For example, an information handling system may take the form of a desktop, server, portable, laptop, notebook, or other form factor computer or data processing system. In addition, an information handling system may take other form factors such as a personal digital assistant (PDA), a gaming device, ATM machine, a portable telephone device, a communication device or other devices that include a processor and memory.

p-0023The Trusted Platform Module (TPM <b>195</b>) shown in <figref idrefs="DRAWINGS">FIG. 1</figref> and described herein to provide security functions is but one example of a hardware security module (HSM). Therefore, the TPM described and claimed herein includes any type of HSM including, but not limited to, hardware security devices that conform to the Trusted Computing Groups (TCG) standard, and entitled “Trusted Platform Module (TPM) Specification Version 1.2.” The TPM is a hardware security subsystem that may be incorporated into any number of information handling systems, such as those outlined in <figref idrefs="DRAWINGS">FIG. 2</figref>.

p-0024<figref idrefs="DRAWINGS">FIG. 2</figref> provides an extension of the information handling system environment shown in <figref idrefs="DRAWINGS">FIG. 1</figref> to illustrate that the methods described herein can be performed on a wide variety of information handling systems which operate in a networked environment. Types of information handling systems range from small handheld devices, such as handheld computer/mobile telephone <b>210</b> to large mainframe systems, such as mainframe computer <b>270</b>. Examples of handheld computer <b>210</b> include personal digital assistants (PDAs), personal entertainment devices, such as MP3 players, portable televisions, and compact disc players. Other examples of information handling systems include pen, or tablet, computer <b>220</b>, laptop, or notebook, computer <b>230</b>, workstation <b>240</b>, personal computer system <b>250</b>, and server <b>260</b>. Other types of information handling systems that are not individually shown in <figref idrefs="DRAWINGS">FIG. 2</figref> are represented by information handling system <b>280</b>. As shown, the various information handling systems can be networked together using computer network <b>200</b>. Types of computer network that can be used to interconnect the various information handling systems include Local Area Networks (LANs), Wireless Local Area Networks (WLANs), the Internet, the Public Switched Telephone Network (PSTN), other wireless networks, and any other network topology that can be used to interconnect the information handling systems. Many of the information handling system include nonvolatile data stores, such as hard drives and/or nonvolatile memory. Some of the information handling systems shown in <figref idrefs="DRAWINGS">FIG. 2</figref> are depicted with separate nonvolatile data stores (server <b>260</b> is shown with nonvolatile data store <b>265</b>, mainframe computer <b>270</b> is shown with nonvolatile data store <b>275</b>, and information handling system <b>280</b> is shown with nonvolatile data store <b>285</b>). The nonvolatile data store can be a component that is external to the various information handling systems or can be internal to one of the information handling systems. In addition, removable nonvolatile storage device <b>145</b> can be shared amongst two or more information handling systems using various techniques, such as connecting the removable nonvolatile storage device <b>145</b> to a USB port or other connector of the information handling systems.

p-0025<figref idrefs="DRAWINGS">FIG. 3</figref> is a system diagram showing an information handling system with a network adapter receiving remote security commands over a computer network. Information handling system <b>100</b> includes network adapter <b>300</b>, such as a wireless wide-area network (WWAN) card, as shown. In a preferred embodiment, this network adapter is “ON” whenever information handling system is powered up, enabling the information handling system to receive commands to, in the case where the system has been lost or stolen, lock the information handling system so that information stored on the information handling system's hard drive cannot be accessed. As used herein, “network adapter” includes any wired or wireless network adapter that allows the information handling system to communicate with another information handling system, such as using computer network <b>200</b>. Examples of network adapters include Ethernet adapters, Token Ring adapters, wireless 802.11 type adapters, Bluetooth adapters, and any other adapter that allows the information handling system to connect to another information handling system and/or a computer network, such as computer network <b>200</b>.

p-0026Administrator <b>305</b>, such as the owner of the information handling system or an IT professional in an organization responsible for asset protection and security, sends commands <b>310</b> to the information handling system. Commands <b>310</b>, such as “lock system,” are transmitted through computer network <b>200</b>, such as the Internet, and are received by the information handling system's network adapter <b>300</b>. Obviously, network adapter <b>300</b> is a critical point in the communications path between administrator <b>305</b> and information handling system <b>100</b>. A malevolent user, such as a thief, of information handling system <b>100</b> may attempt to thwart the reception of commands designed to protect assets stored on information handling system <b>100</b> by removing or otherwise disabling network adapter <b>300</b>. When this occurs, however, the information handling system identifies that the network adapter has been removed or disabled and responds by taking various security measures as described in <figref idrefs="DRAWINGS">FIGS. 4 to 6</figref>.

p-0027<figref idrefs="DRAWINGS">FIG. 4</figref> is a flowchart showing steps taken to setup policies used by the information handling system when the network adapter is removed. Setup is performed by user <b>410</b>. User <b>410</b> may only be the user that sets up the information handling system (e.g., an administrator or IT professional), with a different user being assigned the information handling system after it has been set up. This is especially the case if the organization desires that passwords that are utilized by the system when tampering is evident are unknown to the assigned user and, instead, are only known to the IT professionals with responsibilities for protecting the organization's information assets.

p-0028Processing commences at <b>400</b> whereupon, at step <b>420</b>, the information handling system receives the hard drive password this is to be used if the network adapter is removed from the information handling system. For example, the policy can be established to set the hard drive password to the system's supervisory password (SVP), the power-on password (POP), or another password. In one embodiment, the password (such as the SVP) is unknown to the user of the information handling system but, instead, is known by the IT department in an organization. This embodiment prevents the user from knowingly or unknowingly divulging the password to others, such as a thief of the system. At step <b>425</b>, the hard drive password policy is stored in nonvolatile memory area <b>450</b> that is accessible by an initialization process (e.g., the BIOS) that executes when the information handling system is initialized.

p-0029At step <b>430</b>, the information handling system receives the new power-on password that is to be used if the network adapter is removed from the information handling system. For example, the policy can be established to set the hard drive password to the system's supervisory password (SVP) or another password. In one embodiment, the password (such as the SVP) is unknown to the user of the information handling system but, instead, is known by the IT department in an organization. This embodiment prevents the user from knowingly or unknowingly divulging the password to others, such as a thief of the system. At step <b>435</b>, the power-on password policy is stored in nonvolatile memory area <b>450</b> that is accessible by an initialization process. At step <b>440</b>, a tamper evident indicator, such as a tamper evident bit, is initialized to “NO” (e.g., “0”) to indicate that no tampering is evident with regards to the information handling system's network adapter. This tamper evident indicator is stored in nonvolatile memory <b>450</b>. When tampering is detected, this bit will be set to “YES” (e.g., “1”) and initialization processing will take appropriate security measures to protect the information handling system by setting the hard drive password and the power-on passwords as described in <figref idrefs="DRAWINGS">FIGS. 5 and 6</figref>. Setup processing thereafter ends at <b>495</b>.

p-0030<figref idrefs="DRAWINGS">FIG. 5</figref> is a flowchart showing steps taken when the network adapter is removed while the information handling system is operating. As used herein, the term “removed” when used in relation to the information handling system's network adapter includes both physically removing the network adapter from the information handling system (e.g., removing a Wireless Wide Area Network (WWAN) card from the information handling system, etc.) as well as disabling the network adapter (e.g., turning the network adapter off so that network communications cannot be received, damaging the network adapter, or otherwise disabling the network adapter) so that the network adapter is “removed” from communicating with the information handling system.

p-0031Processing commences at <b>500</b> whereupon, at step <b>510</b>, the network adapter is checked to ensure that the network adapter has not been removed (physically removed or disabled) from the information handling system. A determination is made as to whether the network adapter is electrically present in the information handling system (decision <b>520</b>). If the network adapter, such as a Wireless Wide Area Network (WWAN) card, is electrically present in the information handling system, then decision <b>520</b> branches to “yes” branch <b>515</b> to continually check for the presence of the network adapter (e.g., checking for the presence of the card every few seconds).

p-0032On the other hand, upon one of the checks it is detected that the network adapter has been removed (e.g., physically removed, disabled, damaged, or otherwise unable to receive network communications) then decision <b>520</b> branches to “no” branch <b>525</b> for appropriate handling. At step <b>530</b>, the tamper evident indicator (e.g., a tamper evident bit, etc.) is set in nonvolatile memory <b>450</b> to indicate that tampering has occurred with the network adapter (e.g., by setting the indicator to “YES,” “TRUE,” “1,” or whatever value is used to indicate tampering). At step <b>535</b>, the hard disk password policy is read from nonvolatile memory <b>450</b> that indicates how the hard drive password should be set if tampering is detected (e.g., the policy may be to set the hard drive password to a “supervisory” password, or some other password). At step <b>540</b>, the power-on password policy is read from nonvolatile memory <b>450</b>. The power-on password policy indicates how the power-on password should be set if tampering is detected (e.g., changing the normal power-on password to the supervisory password, requiring both the normal power-on password as well as the supervisory password during power-on sequencing, etc.). At step <b>545</b>, the hard drive password <b>555</b> that protects files stored on one or more hard drives <b>550</b> is changed according to the hard drive password policy that was read at step <b>535</b>. At step <b>560</b>, power-on password <b>570</b> that is stored in nonvolatile memory is changed according to the power-on password policy read at step <b>540</b>. After the hard drive password and the power-on password have been set according to appropriate policies, at step <b>580</b> the system is shutdown requiring the user (e.g., someone who has stolen the information handling system, etc.) to restart the system. At predefined process <b>590</b> the system is restarted by the user and during the startup process (described in <figref idrefs="DRAWINGS">FIG. 6</figref>), steps are taken to protect the information handling system and the information stored therein.

p-0033<figref idrefs="DRAWINGS">FIG. 6</figref> is a flowchart showing steps taken by the information handling system during initialization to check for tampering and the presence of the network adapter. Processing commences at <b>600</b> whereupon, at step <b>602</b>, the tamper evident indicator (e.g., tamper evident bit, etc.) stored in nonvolatile memory <b>450</b> is checked to see whether tampering with the network adapter was detected during a previous use of the information handling system. A determination is made as to whether the tamper evident indicator indicates that tampering (e.g., removing, damaging, disabling, etc.) of the network adapter has taken place (decision <b>604</b>). If tampering is evident based on the indicator, then decision <b>604</b> branches to “yes” branch <b>606</b> whereupon, at step <b>608</b>, the startup sequence requests one or more power-on passwords from the user according to the power-on password policy (e.g., require the supervisory password (SVP), require both the SVP and the normal power-on password, etc.). At step <b>610</b>, the passwords provided by the user are validated. A determination is made as to whether the password responses provided by the user are the correct passwords (decision <b>612</b>). If one or more of the passwords are not correct, then decision <b>612</b> branches to “no” branch <b>614</b> and processing loops back and requests that the user re-enter the passwords. In one embodiment, a time delay is incorporated so that a thief or malevolent user cannot rapidly try guessing the passwords (e.g., using a hacking routine, etc.). In a further embodiment, the time delay is increased in each loop of branch <b>614</b> further thwarting efforts of a thief or unauthorized user. On the other hand, if the user (e.g., a system administrator with knowledge of the SVP, an authorized user, etc.) enters the correct password(s), then decision <b>612</b> branches to “yes” branch <b>616</b> and the user is allowed access to the information handling system and the files stored on the hard drives.

p-0034Returning to decision <b>604</b>, if the tamper evident indicator does not indicate that tampering occurred during a previous use of the information handling system, then decision <b>604</b> branches to “no” branch <b>620</b> in order to ascertain whether the network adapter was removed (e.g., physically removed, disabled, damaged, or otherwise unable to receive network communications) while the information handling system was turned off (before the startup sequence shown in <figref idrefs="DRAWINGS">FIG. 6</figref> commenced). At step <b>622</b>, the network adapter is checked to see if the network adapter has been removed (e.g., physically removed, disabled, damaged, or otherwise unable to receive network communications) from the information handling system. A determination is made as to whether the network adapter has been removed (decision <b>624</b>). If the network adapter has not been removed (e.g., is able to receive network communications and has not been disabled, damaged, etc.) then decision <b>624</b> branches to “no” branch <b>625</b> whereupon, at step <b>626</b> normal startup of the information handling system commences. Normal startup of the information handling system includes the user entering the normal power-on password (if one has been established for the system). In addition, note that during normal operation of the information handling system, the status of the network adapter is periodically checked as shown in <figref idrefs="DRAWINGS">FIG. 5</figref> so that if the network adapter is removed after the system is started, appropriate steps are taken to protect the information handling system and the data stored therein.

p-0035On the other hand, if it is detected that the network adapter has been removed (e.g., physically removed, disabled, damaged, or otherwise unable to receive network communications) prior to the information handling system being turned on, then decision <b>624</b> branches to “yes” branch <b>628</b> for appropriate handling. At step <b>630</b>, the tamper evident indicator (e.g., a tamper evident bit, etc.) is set in nonvolatile memory <b>450</b> to indicate that tampering has occurred with the network adapter (e.g., by setting the indicator to “YES,” “TRUE,” “1,” or whatever value is used to indicate tampering). At step <b>635</b>, the hard disk password policy is read from nonvolatile memory <b>450</b> that indicates how the hard drive password should be set if tampering is detected (e.g., the policy may be to set the hard drive password to a “supervisory” password, or some other password). At step <b>640</b>, the power-on password policy is read from nonvolatile memory <b>450</b>. The power-on password policy indicates how the power-on password should be set if tampering is detected (e.g., changing the normal power-on password to the supervisory password, requiring both the normal power-on password as well as the supervisory password during power-on sequencing, etc.). At step <b>645</b>, the hard drive password <b>555</b> that protects files stored on one or more hard drives <b>550</b> is changed according to the hard drive password policy that was read at step <b>635</b>. At step <b>660</b>, power-on password <b>570</b> that is stored in nonvolatile memory is changed according to the power-on password policy read at step <b>640</b>. At step <b>665</b>, processing loops back to step <b>602</b>. Now, the tamper evident indicator has been set and appropriate steps will be taken to protect the information handling system and the data stored therein (decision <b>604</b> will now branch to “yes” branch <b>606</b> and request one or more power-on passwords according to the power-on password policy).

p-0036One of the preferred implementations of the invention is a client application, namely, a set of instructions (program code) or other functional descriptive material in a code module that may, for example, be resident in the random access memory of the computer. Until required by the computer, the set of instructions may be stored in another computer memory, for example, in a hard disk drive, or in a removable memory such as an optical disk (for eventual use in a CD ROM) or floppy disk (for eventual use in a floppy disk drive), or downloaded via the Internet or other computer network. Thus, the present invention may be implemented as a computer program product for use in a computer. In addition, although the various methods described are conveniently implemented in a general purpose computer selectively activated or reconfigured by software, one of ordinary skill in the art would also recognize that such methods may be carried out in hardware, in firmware, or in more specialized apparatus constructed to perform the required method steps. Functional descriptive material is information that imparts functionality to a machine. Functional descriptive material includes, but is not limited to, computer programs, instructions, rules, facts, definitions of computable functions, objects, and data structures.

p-0037While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that, based upon the teachings herein, that changes and modifications may be made without departing from this invention and its broader aspects. Therefore, the appended claims are to encompass within their scope all such changes and modifications as are within the true spirit and scope of this invention. Furthermore, it is to be understood that the invention is solely defined by the appended claims. It will be understood by those with skill in the art that if a specific number of an introduced claim element is intended, such intent will be explicitly recited in the claim, and in the absence of such recitation no such limitation is present. For non-limiting example, as an aid to understanding, the following appended claims contain usage of the introductory phrases “at least one” and “one or more” to introduce claim elements. However, the use of such phrases should not be construed to imply that the introduction of a claim element by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim element to inventions containing only one such element, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an”; the same holds true for the use in the claims of definite articles.